关彬,陈博夫,刘硕

• 1:河海大学水利水电学院
• 2:三峡大学水利与环境学院
• 3:湖北能源集团南漳张家坪抽水蓄能公司

摘要(Abstract)：

【目的】为探究真实温度环境下低热混凝土微观演化规律与宏观力学性能之间的关系，【方法】设计并开展了不同温度(20℃、30℃、40℃)作用下低热混凝土抗压强度和孔结构试验，基于扫描电镜(SEM)图像，结合盒维数法，计算得到了低热混凝土的分形维数，最后建立了考虑分形维数的抗压强度预测模型。【结果】结果显示：高温养护下，低热混凝土的临界孔径、最可几孔径和孔隙率降低，分形维数从1.796 8增加到1.886 8,28 d抗压强度增长了27%。【结论】结果表明，36%～42%的孔隙率和10～20 nm的孔径对应的微观空间状态最为复杂，高温养护增强低热混凝土10～20 nm的孔径含量，有效提高了抗压强度；提出的预测模型可以定量描述低热混凝土力学性能与孔结构分形维数的耦联关系，为不同温度作用下大坝混凝土的耐久性和安全性设计提供了理论支撑。

关键词(KeyWords)： 低热混凝土;温度;孔结构;分形维数;预测模型;力学性能

Abstract:

Keywords:

基金项目(Foundation): 国家自然科学基金青年项目(52109158)

作者(Author): 关彬,陈博夫,刘硕

DOI: 10.13928/j.cnki.wrahe.2024.07.015

参考文献(References)：

• [1] 陈改新，刘艳霞，纪国晋，等.低热硅酸盐水泥在水工混凝土中的应用研究[J].水利水电技术(中英文),2021,52(12):191-200.CHEN Gaixin,LIU Yanxia,JI Guojin,et al.Research on the application of low-heat Portland cement in hydraulic concretes[J].Water resources and hydropower engineering,2021,52(12):191-200.
• [2] 杜敏，武亮，张建铭.长龄期中低热混凝土断裂性能试验研究[J].混凝土，2021(1):57-60.DU M,WU L,ZHANG J M.Fracture performance of long-aged moderate-heat and low-heat concrete[J].Concrete,2021(1):57-60.
• [3] 申嘉荣，徐千军.建筑材料微观结构的人工识别研究[J].水利发展研究，2023,23(10):72-79.SHEN Jiarong,XU Qianjun.Artificial identification of microstructure in building materials [J].Water Resources Development Research,2023,23 (10):72-79.
• [4] 娄许煜，王起才，代金鹏，等.-3 ℃养护环境下粉煤灰对混凝土的强度和孔结构影响[J].混凝土，2019(11):15-18.LOU Xuyu,WANG Qicai,DAI Jinpeng,et al.Effect of fly ash on strength and pore structure of concrete under curing condition of negative temperature(-3 ℃)[J].Concrete,2019(11):15-18.
• [5] 王庆石，张凯，王起才，等.低温养护下引气混凝土的孔结构对力学性能及耐久性能影响研究[J].硅酸盐通报，2015,34(8):2095-2099.WANG Qingshi,ZHANG Kai,WANG Qicai,et al.Effect of the pore structure of air concrete on the mechanical properties and durability at low temperature curing[J].Bulletin of the Chinese ceramic society,2015,34(8):2095-2099.
• [6] 刘伟佳，樊启祥，李庆斌，等.不同温度对混凝土坯层间劈裂抗拉强度影响试验研究[J].水利水电技术(中英文),2021,52(2):200-206.LIU Weijia,FAN Qixiang,LI Qingbin,et al.Experimental research on the effect of different temperatures on the interlayer splitting tensile strength of concrete[J].Water resources and hydropower engineering,2021,52(2):200-206.
• [7] JIN S,ZHANG J,HAN S.Fractal analysis of relation between strength and pore structure of hardened mortar[J].Construction and building materials,2017(135):1-7.
• [8] HAN J,LIU Z,ZHANG C.Experimental study on iMPact resistance of steel-fiber-reinforced two-grade aggregate concrete[J].Construction and building materials,2023(373):130901.
• [9] MU C,HUA H,WANG X.Characterization of pore structure and reservoir properties of tight sandstone with CTS,SEM and HPMI:A case study of the tight oil reservoir in fuyu oil layers of Sanzhao Sag,Songliao basin,NE China[J].Frontiers in energy research,2023(10):1053919.
• [10] PAUN M A,PAUN V A,PAUN V P.Fractal analysis and time series application in ZY-4 SEM micro fractographies evaluation[J].Fractal and fractional,2022,6(8):458.
• [11] 樊水龙.基于SEM的干湿循环蚀变花岗岩分形特征与力学特性演化规律[J].长江科学院院报，2020,37(3):102-107.FAN Shuilong,Evolution of fractal and mechanical properties of cyclic dry-wet altered granite based on SEM[J].Journal of Yangtze River scientific research institute,2020,37(3):102-107.
• [12] 张庆章，方燕，宋力，等.混凝土孔结构及其分形维数与氯离子扩散性能的关系[J].硅酸盐通报，2022,41(8):2716-2727.ZHANG Qingzhang,FANG Yan,SONG Li,et al.Relationship between pore structure,fractal dimension and chloride diffusion performance of concrete[J].Bulletin of the Chinese ceramic society,2022,41(8):2716-2727.
• [13] 蒋科，郭辉，李洋，等.氯盐环境下混凝土冻融循环及孔结构演化研究[J].人民长江，2021,52(12):162-167.JIANG Ke,GUO Hui,LI Yang,et al.Research on concrete damage and pore structure evolution under freeze-thaw cycles in chloride solution[J].Yangtze River,2021,52(12):162-167.
• [14] 孙浩然，邹春霞，薛慧君，等.模袋混凝土干湿-冻融侵蚀孔结构的分形特征[J].建筑材料学报，2022,25(2):124-130.SUN Haoran,ZOU Chunxia,XUE Huijun,et al.Fractal characteristics of dry-wet and freeze-thaw erosion pore structure of mold-bag concrete[J].Journal of building materials,2022,25(2):124-130.
• [15] CUI S,LIU P,CUI E,et al.Experimental study on mechanical property and pore structure of concrete for shotcrete use in a hot-dry environment of high geothermal tunnels[J].Construction and building materials,2018(174):603-612.
• [16] 李温，王海龙，张佳豪，等.胶粉煤矸石混凝土力学特性及微观结构试验研究[J].排灌机械工程学报，2023,41(2):140-146.LI Wen,WANG Hailong,ZHANG Jiahao,et al.Experimental study on mechanical properties and microstructure of powdered coal gangue concrete[J].Journal of Drainage and Irrigation Machinery Engineering,2023,41(2):140-146.
• [18] 霍俊芳，曹雪，王萧萧，等.天然浮石混凝土孔结构对其抗压强度影响的研究[J].硅酸盐通报，2020,39(3):734-739.HUO Junfang,CAO Xue,WANG Xiaoxiao,et al.Influence of natural pumice concrete pore structure on its compressive strength[J].Bulletin of the Chinese ceramic society,2020,39(3):734-739.
• [19] 薛慧君，郑建庭，邹春霞，等.风积沙对引气混凝土强度及孔结构的影响[J].建筑结构，2022,52(8):112-117.XUE Huijun,ZHENG Jianting,ZOU Chunxia,et al.Influence of aeolian sand on strength and pore structure of air-entrained concret [J].Building structure,2022,52(8):112-117.
• [20] 徐存东，李准，连海东，等.不同引气剂掺量早冻混凝土力学性能及孔结构分形特征[J].水电能源科学，2023,41(1):133-136.XU Cundong,LI Zhun,LIAN Haidong,et al.Experimental study on mechanical properties and pore structure fractal characteristic of early freezing concrete with different air entraining agent content[J].Water Resources and power,2023,41(1):133-136.
• [21] 国家能源局.水工混凝土配合比设计规程：DL/T 5330—2015[S].北京：中国电力出版社，2015.National Energy Administration.Code for mix design of hydraulic concrete:DL/T 5330—2015[S].Beijing:China Electric Power Press,2015.
• [22] 中国水利水电科学研究院.水工混凝土试验规程：DL/T 5150— 2001[S].北京：中国电力出版社，2001.China Institute of Water Resources and Hydropower Research.Test code for hydraudic concrete:DLT 5150—2001[S].Beijing:China Electric Power Press,2001.
• [23] 中华人民共和国建设部.普通混凝土力学性能试验方法标准：GB/T 50081—2002[S].北京：中国建筑工业出版社，2003.Ministry of Construction of the People′s Republic of China.Standard for test method of mechanical properties on ordinary concrete:GB/T 50081—2002[S].Beijing:China Architecture Publishing&Media Co.,Ltd,2003.
• [24] 张乐.基于CT图像和改进的差分盒维数法的混凝土细观损伤研究[D].西安：西安理工大学，2017.ZHANG Le.Quantitative study to concrete meso-damage based on CT image and improved differential box counting method[D].Xian:Xian University of Technology,2017.
• [25] 毛灵涛，连秀云，郝丽娜.基于数字体图像三维裂隙的分形计算及应用[J].中国矿业大学学报，2014,43(6):1134-1139.MAO Lingtao,LIAN Xiuyun,HAO Lina.The fractal calculation of 3D cracks based on digital volumetric images and its application[J].Journal of China University of Mining&Technology,2014,43(6):1134-1139.
• [26] 云振军，姚占全，何梁，等.纳米SiO2粉煤灰混凝土抗压强度影响及灰熵分析[J].排灌机械工程学报，2022,40(5):467-474.YUN Zhenjun,YAO Zhanquan,HE Liang,et al.Influence of nano-SiO2 fly ash on compressive strength of concrete and grey entropy analysis[J].Journal of Drainage and Irrigation Machinery Engineering,2022,40(5):467-474.
• [27] 李温，王海龙，张佳豪，等.胶粉煤矸石混凝土力学特性及微观结构试验研究[J].排灌机械工程学报，2023,41(2):140-146.LI Wen,WANG Hailong,ZHANG Jiahao,et al.Experimental study on mechanical properties and microstructure of powdered coal gangue concrete[J].Journal of Drainage and Irrigation Machinery Engineering,2023,41(2):140-146.
• [28] 张韦，刘超，刘化威.基于孔体积分形维数的稻壳灰混凝土冻融损伤劣化机理[J].复合材料学报，2022,40(8):1-13.ZHANG Wei,LIU Chao,LIU Huawei.Freeze-thaw damage deterioration mechanism of rice husk ash concrete based on pore volume fractal dimension[J].Acta materiae compositae sinica,2022,40(8):1-13.